BrainCog is a free online assessment website. Educators can create a free account during the Beta testing period and you will have access to a dashboard that allows you to test students online. When you sign up you provide all the usual information. The difference is you also create a specific BrainCog URL that students will use to access the assessments. A confirmation email is required for registration.
With each assessment you will be provided reports so that you can see student progress. Assessments are limited to multiple choice, but each test can also be a timed test, which is important for ACT and AP test preparation. You can easily import student rosters into the site as well. For each test you provide an intro message, a fail message, a pass message, and an email reminder. Several valuable tools that would be worth trying with students to see how the program could work in your classroom.
BrainCog is worth signing up for while it is still in Beta.